Light regulation of carbon fixation in diatoms

• Applicant: Professor Dr. Peter Kroth
• Subject Area: Plant Physiology
• Term: from 2009 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 112805507

This project focuses on the light-driven regulation of the photosynthetic Calvin cycle in diatoms. Our recent work has shown that regulation mechanisms known from land plants like the redox regulation via thioredoxin are strongly reduced in diatom plastids. So far the Fructose-1,6-bisphosphatase (FBPase) is the only Calvin cycle enzyme in diatoms known to be redox-regulated. As there is evidence that transcription of some Calvin cycle enzymes like phosphoribulokinase (PRK) and glyceraldehyde-3-phosphate dehydrogenase (GAPC1) may be increased in blue light conditions, we want to study the role of blue light receptors in diatoms. First we have studied the expression of key enzymes via quantitative PCR and western blots analysis and detected changes based on the presence of blue light well as on a diurnal rhythm. In this proposal we now want to study and compare expression of selected Calvin cycle enzymes in cells grown at blue light conditions, to investigate the role of FBPase complexes for the respective enzyme activities, and to characterize the light-driven properties of the GAPC1 and PRK promoters.

• DFG Programme: Research Units
• Subproject of: FOR 1261: Specific Light Driven Reactions in Unicellular Model Algae